Reversible fan



April 13, 1965 L. T. cAsToN 3,177,949

REVERSIBLE FAN Filed May 7, 1963 2 Sheets-Sheet l INVENTOR Lowe/l T.Gas/0n ATTORNEY 1.. 'r. CASTON REVERSIBLE FAN A ril 13, 1965 2Sheets-Sheet 2 Filed May '7, 1963 ATTORNEY United States Patent3,177,949 REVERSELE FAN Lowell T. Caston, Robert Lee, Tex. Filed May 7,1963, Ser. No. 278,795 1 Claim. (Ci. fill-160.43)

This invention relates to a reversible fan, and more particularly to anindustrial type of fan wherein the pitch of the fan blades may bereversed while the fan continues to rotate.

A further object of this invention is to provide an industrial typereversible fan which is very simple in construction and in operation,which may be readily taken apart for servicing and readily assembled orreassembled with ordinary tools. 7

Still a further object of this invention is to provide a reversible fanwherein the pitch of the fan blades may be changed between a forward anda reverse position, as

I well as a neutral or feathering position.

Still a further object of thisinvention is to provide an industrial typeof reversible fan for use wherever desired, and particularly, for use inconnection with an industrial engine such as on a drilling rig, or moreparticularly, on a crawler type of tractor, wherein the operator mayadjust the pitch of the blade as desired, while the motor is operatingthus placing the pitch of the blade at a neutral or feathering positionwhen the engine is first started, enabling the engine to warm up morequickly, then shifting the blade to a position to suck air through theengine radiator and to keep the engine at proper temperature. However,when desired, the pitch of the blade may be readily reversed while theengine continues to operate, so as to blow against the radiator, ifnecessary as, for instance, when the radiator'may have accumulated somebrush, trash or dirt thereon interfering with cooling, as may wellhappen when it is used in areas having a lot of brush or trash.

Still a further object of this invention is to provide a rotary fanhaving a reversible pitch controlled by a rack and gear connection toeach fan blade shaft, wherein the rack may be readily moved to differentpositions while the fan blade is rotated, to controllably change thepitch of the fan blade between forward, neutral and reverse positions.

With the above and related objects in view, this invention consists inthe details of construction and combination of parts as will be morefully understood from the following description, when read inconjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view of the fan of this invention.

FIG. 2 is a sectional view on line 22 of FIG. 1, extendinglongitudinally of the fan blade mounting.

FIG. 3 is a transverse sectional view on line 3-3 of FIG. 2.

FIG. 4 is a sectional view through the rack and gear control means online 44 of FIG. 2.

There is shown at 10 the fan of this invention, consisting of one ormore fan blades 12 secured on a fan blade shaft 14, the fan blade shaft14 extending into the blade rotating unit 16. The fan blade rotatingunit 16 consists of an outer sleeve 18, a concentric inner sleeve 20spaced within the outer sleeve 18, and a cylindrical rack sleeve 22axially slidable between the outer sleeve 18 and the inner sleeve 20.

The outer sleeve 18 and the inner sleeve 20 are secured for operation asunit 16 by the fan blade shafts 14 extending through aligned journalopenings 32 and 34 in the outer and inner sleeves 18 and 20, and heldthereto by nuts 36 threaded on the inner ends thereof.

The axle or sleeve 22 extending between the inner and outer sleeves isprovided with an axially extending slot 38 for each fan blade 14 so thatthe sleeve 22 may be extended sufificiently beyond the fan blade shaft14, and one axially extending wall of each slot 38 has rack teeth 40formed therein and meshing with the teeth of a gear 42 which is fixed onthe fan blades 14, One slot 38 with its rack 40 is provided for each fanblade shaft 14, six such blades and fan blade shafts being shown herein.

As will be apparent from FIG. 2, axial sliding movement of the racksleeve 22 in one direction or the other will correspondingly rotate thefan blade shafts 14, and thus the fan blades 12. The ratio of the gear42 to the rack 40 is such that the blades 12 may be set between aforward pitch for normal operation in the case of the radiator, forsucking air through the radiator, a neutral pitch (or a feather pitch)wherein no air is moved, as when speeding up the heating of the engine,and a reverse pitch wherein air is blown against the radiator so as toclean out any dust, trash or debris that may accumulate there- To holdthe blades at any one of these three positions, four cooperating detents44 with springs 46 urging them outwardly of recesses in the rack 22 isprovided, and four sets of each three detent-receiving recesses 48, 50and 52 are provided in one of the sleeves, here shown as the outersleeve 18. When the detents are in the recesses 50, the

blade 12 is in the neutral or feathering position, as illustrated.Pushing the rack 40 axially in a right hand direction as illustrated inFIGS. 1 and 2, will cause'the blade to rotate in a position to cause airto move in a left direction, while moving the rack 40 so as to bring thedetents 44 into the recesses 52 will makethe air move in the oppositedirection.

In order to slide the rack 40 one way or the other, and still permit itto rotate as a part of the unit 16, with the outer sleeve 18 and innersleeve 20, a thrust bearing 54 is secured on one end of the rack sleeve22. The outer race 56 of thrust bearing 54 is provided with a pair ofdiametrically opposed bosses 58 cooperating with the slots 60 of a fork62 having a control lever 64 pivoted by a stud bolt 66 to a support arm68, so that movement of the control lever 64 through the slot 60 andboss 58 will axially move the thrust bearing 54, and thus the racksleeve 22 secured thereto, to thus control the rotation of the fan bladeshaft 14 and the positioning of the blades 12.

The fan blade unit 16 is powered for rotation in any conventionalmanner. As here shown, a pulley 70 is mounted on the outer side of thesleeve 18 of the unit 16 for operation by a pulley belt from the engine(not shown) in a conventional manner. The fan blade unit 16 is mountedfor ready rotation by having a pair of bearings 72 mounted therewithinon a bearing shaft 74 in a conventional manner. A nut 76 is provided atthe outer end of the bearing shaft 74.

In operation, the manner of assembling or disassembling the parts of thefan 10 of this invention is obvious from the foregoing description. Withthe engine running, and thus the fan unit 16 in rotation, the fan blades12 may be set at one of the three desired positions by manipulating thelever 64 so as to advance or retract the rack sleeve or cylinder 22.When the spring pressed detents 46 have been brought to the position ofbeing in the detent recesses 50, the fan blades 12 are in a neutral orfeathering position, and will not move air in either directions.Advancing the sleeve rack 22 by manipulating the lever 64 to bring theball detents 44 to the recesses 52 will cause the air to move in onedirection, while retracting the rack sleeve 22 to bring the ball detents44 into the recesses 48 will cause to reverse its pitch to move the airin the opposite direction.

Q.D The normal direction of operation will be to suck air through theengine radiator, but when the engine is part of a crawler tractor,forinstance, and operating where there is a lot of dirt, brush or debrisprsent, some of the dirt, dust or debris will tend to accumulate onthe'radiator and clog the pores thereof/thnseausing the motor tooverheat. Instead of permitting such dust or dirt to accumulate, theoperator'niay manipulate the lever 64 every once in a while to reversethe pitch of the fan blades 12 tocause the air to travel'inthe oppositedirection and blow away the accumulated dirt, dust or debris'before ithas accumulated a sufiicient amount to cause overheating of the engine,"and then the blade pitch is again reversed, to cause ittocool theradiator in the'normal manner. This'operation can continue withoutstopping the engine, or even stopping the operation of the unit on whichthe engineis mounted. The operator momentarily manipulatesfthe leverf64so as to keep the radiator continuously clean. V I t In addition tobeing used on vehicles such as a crawler type tractor, itcan'be alsoused on'drilling rigs or other stationaryengi nes thusenabling suchengines to be 10- to be determined as claimed. r 7

Having thus set forth'an'd disclosed the nature of this "invention, whatis claimed is:

'trative-rather then limitingQsince the inventions may be a t i Areversible fan comprising a pair of concentric'sep' arate Spaced apartcylindrical sleeves, a fan blade shaft 'journale'd radially throngh'saidtwo concentric sleeves and holding said cylindrical sleeves againstmovement relative to each other, a gear fixed on said fan blade'shaft,in the space between said two concentric sleeves, a cylindrical sleeveaxially slidable between said two spaced apart concentric sleeves, saidaxially slidable sleeve having an axially extending slot therein andrack teeth integrally formed on one axially extending wall of said slotin mesh with said gear fixed on said fan blade shaft, and means foraxially sliding and holding said cylindrical sleeve to rotate said fanblade shaft and means to hold it in set positions while said threesleeves are rotating as a unit, said sliding means comprising-thrustbearing means mounted onsaid cylindrical rack sleeve, a forked levercooperating with said thrust bearing to axially slide said cylindricalrack sleeve between said Itv'vo spaced apart concentric sleeves, saidholding means comprising spring pressed detent means, and spaced apartdetent cooperating recesses cooperatively ni'otinted'in said cylindricalrack sleeve and one of said concentric sleeves, a bearing shaftextending'through said inner concentric sleeve, and spaced bearing meansadjacent opposite ends of and within said innerfsleeve rotatablysupporting said sleeves as a unit on said bearing shaft, and'powerreceiving means comprising 'a pulley fixedly'mounted on and about saidouter concentric sleeve.

References Cited by the'Examiner UNITED STATES PATENTS 785,369 3/05Meinecke -16043 1,391,517 9/21 501111 ITO-160.42 1,509,944 9/24'Forgette 170-16038 1,514,874 Ill/24 Street 170-16042 1,560,173 11/25Ehinger 170-16042 1,636,286 7/,27 Christensen 170-16042 1,712,883 5/29Groner 170-16042 2,533,148 12/50 Spiegel 170-16042 EDGAR W.GEOGHEGAN,Primary Examiner. JULIUS E. WEST, Examiner.

